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Why Use Organic Matter in the Garden? Improve Fertility!

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Ask any keen gardener you know about using organic matter on their plot, and they will be sure to tell you all about the fantastic results they have had with it.

Adding organic matter to your garden adds vital nutrients to the soil. It also feeds the microorganisms that are crucial in maintaining the structure of the soil. As a result, the fertility of your soil is greatly improved.

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All plants benefit from growing in soil rich in organic matter, from flowers to fruit and veg.

So, what’s the secret of this amazing stuff, and why should you use it in your garden? Read on to find out.

What is Soil Fertility?

Picture of cupped hands holding wood chips

The fertility of your garden’s soil is its ability to provide an ideal habitat where plants can thrive.

To achieve this, the soil should be rich in essential plant nutrients and retain and drain moisture in just the right amounts to give your plants what they need. One of the key indicators of the level of fertility your soil has is the soil structure.

As a general rule of thumb, pale soil that either dries out rapidly or doesn’t dry out at all is likely to be relatively infertile.

Dark, rich, moist, crumbly soil that smells like a walk through a wet forest shows all the signs of being highly fertile!

But not all garden soils are created equal, and you may have noticed tell-tale signs that yours is less than fully fertile.

Never fear, though! Adding some well-chosen organic matter can work wonders to improve the structure, boost fertility and give your soil the oomph it needs to let your plants flourish.

Essentially, all life depends upon the soil… There can be no life without soil and no soil without life; they have evolved together.

Dr. Charles E Kellogg

What is Organic Matter for the Garden?

First, what is this amazing stuff that will transform your soil?

In simple terms, organic matter in gardening refers to once-living materials added to the soil to improve its quality.

Organic matter is sometimes referred to as a ‘soil improver’ or ‘soil conditioner,’ and many materials can be used.

Using organic matter in your garden goes way beyond just compost!

What are the Best Types of Organic Matter to Use in My Garden?

Some examples of organic matter that you may have heard of include:

  • Fallen leaves are most beneficial after being composted or turned into leaf mulch.
  • Homemade compost: made from suitable kitchen and garden waste.
  • Municipal compost: This is often available through local authorities. It’s composted in larger heaps than most home composts, so the temperatures are higher, and there are less likely to be weeds in the compost.
  • Animal manure: This can be used either rotted down or fresh, depending on your purposes and is often available for sale (or free if you’re lucky) from local farmers and stables. You’ll get the best results using manure for nitrogen-loving plants like potatoes, corn, or your lawn.
  • Straw: This is another fantastic natural mulch that you can use to prevent weed growth and aid moisture retention. It can also be a protective layer for more delicate plants as they lay dormant over the winter.
  • Cover crops: This is an example of organic matter benefiting your growing garden. Cover crops include Alfalfa, Buckwheat, and Rye, which are a literal cover for your soil. They can help you control soil erosion, moisture retention, and weed suppression while encouraging wildlife in your garden.

I have a video about proven cover crops. You can watch it below.

How Does Adding Organic Matter Improve Fertility?

In wild places, plants naturally spring up in the most fertile soils and, therefore, the easiest to establish themselves.

The rich ‘black gold’ you will see in fertile soil is the end product of plenty of decomposed organic matter. It’s known as hummus, and although it’s not the tasty kind humans eat, plants find it just as delicious!

This super-fertile soil is created by the nitrogen cycle, which, in straightforward terms, operates like this:

  • Plant and animal wastes decompose, adding nitrogen to the soil.
  • Bacteria in the soil convert those forms of nitrogen into forms plants can use.
  • Plants use the nitrogen in the soil to grow.
  • People and animals eat the plants; then, animal and plant residues return nitrogen to the soil, completing the cycle.

We are trying to replicate the nitrogen cycle when we use organic matter in our gardens because most domestic gardens are artificially created; we must add the organic matter needed to create fertile soil.

How to Use Organic Matter in Your Garden

We’ve already discussed some materials you can use as organic matter in your garden, but they are not all applied similarly. Here are some of the different ways I like to put organic matter to work:

As a Mulch

Mulch is super beneficial for your soil’s fertility. It is a layer of material added to the surface. Mulch acts like a lovely blanket that protects the soil from getting dried out by the sun and blown away by the wind when applied properly.

Mulch also makes it much harder for weeds to break through and lock in moisture. In the long term, this will make life much easier for you. I’m sure you’ll agree that the less weeding and watering you need to do, the better!

Although non-organic matter mulches are available, they are not nearly as beneficial. When you use nutrient-rich organic matter, the soil gets the added benefit of absorbing these nutrients as the mulch begins to break down. This process mimics the all-important nitrogen cycle that I mentioned earlier.

I have a video about proven garden mulch ideas. You can do that below.

As a Fertilizer

Adding fertilizer is a great way to target the specific nutritional needs of your soil. Some plants may enjoy nitrogen-rich growing conditions, while others thrive on higher potassium levels like tomatoes and flowering plants.

Fertilizer delivers the required nutrients to your plants in the most readily available form.

You will no doubt have seen plenty of chemical fertilizers available for sale on the shelves of your local garden center. While these are crafted to combine the ideal levels of certain nutrients for plants, they often do not benefit the structure of the soil itself.

Organic matter as a fertilizer provides the nutrients plants need and is fantastic for improving the soil structure. Soil rich in organic matter retains moisture and nutrients for longer, resulting in the soil’s long-term fertility.

Of course, different types of organic matter contain different levels of nutrients, and you’ll want to be sure that you’re applying the right stuff to get the maximum benefits for your soil.

The best way to do this is to carry out a soil test.

Once you know what your soil lacks, you can choose the best organic materials to boost it.

Nutrient DeficiencyOrganic Matter to Use
NitrogenPoultry Manure (pelleted form makes the nitrogen most readily available)
PhosphorusBone Meal
MagnesiumEpsom Salts (yes, the ones you can bathe in!)
As you can see, most nutrient deficiencies in the soil can be remedied through organic matter.


Making your compost out of organic material from your kitchen and garden is satisfying. Knowing that you’re creating something beneficial to your soil and plants can greatly boost your confidence as a gardener.

The key to getting the most from all that lovely compost you’ve nurtured is to ensure it’s properly rotted down before using it.

As I mentioned earlier in the post, things like wood chippings and cuttings can deplete the soil’s nitrogen if they’re not well-rotted.

The minimum time for compost to be useable is around six months, but it can take as long as two years to reach its best.  You’ll know it’s just right when the color is dark brown, has a crumbly texture, and smells like wet autumn leaves.

The best time of year to dig compost into your soil is spring before most plant growth has picked up speed.

It may seem like a lot of work to make compost yourself, but trust me; it’s worth it!

I have a video about why you should make compost at home. Watch it below.

As a Compost Activator

Some compost heaps are stubborn! You may find that yours is taking a long time to get to the ideal consistency, or maybe it just doesn’t seem to be getting started at all!

In most cases, the ingredient that is lacking is sufficient nitrogen. This is where compost activators come in handy. These clever substances stimulate composting to help start or speed up decomposition.

You can use organic matter in this way too. Here are a few materials I’d recommend to give your sluggish compost heap the shot of nitrogen it needs to get moving

Green Plants

Comfrey, clover, alfalfa, and other green plants, are all high in readily available nitrogen. They benefit the soil when growing and also make excellent compost activators.

Picture of clover


Picture of soil with manure

Certain types of well-rotted manure can boost your nitrogen content and kick-start composting. Take care when adding it, though. Fresh manure can burn plant roots, so a mature option is always best. Use the manure as a green, nitrogen-rich layer in your compost system, and be sure to sandwich it between two brown, carbon-rich layers to get the best results.

Coffee grounds

Most of us crave that first caffeine hit of the morning, but it may not have occurred to you that it could also boost your soil! Coffee grounds contain a reasonable amount of nitrogen and are a worthwhile addition to your compost heap or bin.

Picture of spooning coffee grounds around a plant pot
Dont toss your coffee grounds in the trash Your compost heap will thank you for the nitrogen boost

Conclusion on why use organic matter in the garden

The higher the level of well-broken-down organic matter in the soil, the more fertile that soil becomes. So, your plants benefit from all the moisture and nutrients that lovely hummus provides.

As we have seen, there are loads of different ways to incorporate organic matter into your garden and many materials you can use. The best part is that many are free and already in your home or garden, so you can get stuck immediately!

I hope this post has given you an idea of how beneficial the use of organic matter in your garden is to your soil’s fertility.

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